package com.school.common.util;

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import com.school.common.constant.Constant;

/**
 * @author
 * 
 */
public class AesUtils {

	/**
	 * AES加密算法
	 */
	public AesUtils() {
	}

	/**
	 * @param content
	 *            需要加密的内容
	 * @param password
	 *            加密密钥
	 * @return String 加密后的字符串
	 */
	public static String encrypttoStr(String content, String password) {
		return parseByte2HexStr(encrypt(content.getBytes(), password));
	}

	/**
	 * 将二进制转换成16进制
	 * 
	 * @param buf
	 * @return String
	 */
	public static String parseByte2HexStr(byte buf[]) {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < buf.length; i++) {
			String hex = Integer.toHexString(buf[i] & 0xFF);
			if (hex.length() == 1) {
				hex = '0' + hex;
			}
			sb.append(hex.toUpperCase());
		}
		return sb.toString();
	}

	/**
	 * 将16进制转换为二进制
	 * 
	 * @param hexStr
	 * @return byte[]
	 */
	public static byte[] parseHexStr2Byte(String hexStr) {
		if (hexStr.length() < 1)
			return null;
		byte[] result = new byte[hexStr.length() / 2];
		for (int i = 0; i < hexStr.length() / 2; i++) {
			int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
			result[i] = (byte) (high * 16 + low);
		}
		return result;
	}

	public static byte[] encrypt(byte[] content, String password) {
		try {
			SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES");
			IvParameterSpec ivspec = new IvParameterSpec("vYdKUfTV01TA4t41".getBytes());

			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
			byte[] byteContent = content;
			cipher.init(Cipher.ENCRYPT_MODE, key, ivspec);// 初始化
			byte[] result = cipher.doFinal(byteContent);
			return result; // 加密
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		} catch (InvalidAlgorithmParameterException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}

	public static byte[] decrypt(byte[] content, String password) {
		try {
			SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES");
			IvParameterSpec ivspec = new IvParameterSpec("vYdKUfTV01TA4t41".getBytes());
			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
			byte[] byteContent = content;
			cipher.init(Cipher.DECRYPT_MODE, key, ivspec);// 初始化
			byte[] result = cipher.doFinal(byteContent);
			return result; // 加密
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		} catch (InvalidAlgorithmParameterException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * @param content
	 *            待解密内容(字符串)
	 * @param keyWord
	 *            解密密钥
	 * @return byte[]
	 */
	public static byte[] decrypt(String content, String keyWord) {
		return decrypt(parseHexStr2Byte(content), keyWord);
	}

	public static void main(String[] args) {
		String str = "system";
		if (args != null && args.length > 0) {
			str = args[0];
		}
		String encryptResult = encrypttoStr(str, Constant.AES_KEY);
		System.out.println("Encrypt Result:" + encryptResult);
	}
}